Amarkhil added that Rutherford had been released at 11 a.m. on Monday in Ghazni province's remote Giro district.

The involvement of Qatar in Rutherford's release is not entirely surprising.

The Persian Gulf country has at times quietly played mediator between western governments and the Taliban -- even helping to facilitate peace negotiations between governments in Kabul and the hardline insurgency.

The Taliban have openly maintained a political office in the Qatari capital of Doha since 2013.

The Qatari Embassy in Ottawa did not immediately respond to a request for comment on Rutherford's release.

The last indication Rutherford's family had that he was alive came in a 2011 video released by insurgents where he answered questions; an accompanying email accused Rutherford, then 26, of being a spy.

In the video, Rutherford, who is from Toronto, insisted he was not a spy and had travelled to Afghanistan to study historical sites, old buildings and shrines.

Rutherford's brother Brian has called the Canadian's release "incredible news."

"It absolutely is an enormous relief," he said in a message to The Canadian Press. "My deepest gratitude to all those whose efforts have aided in Colin's safe release."

He added that the family is "obviously looking forward" to being reunited with Rutherford and said his well-being was a priority.

Rutherford was working as an auditor with the Canadian Circulations Audit Board in Toronto when he went on vacation to Afghanistan.